Offspring of depressed mothers are at increased risk for developing behavior and psychological disorders later in life. Although there is certainly a genetic component for this increased vulnerability, it is also likely that the early environment of the infant and child plays a role in determining which individuals will develop disorders versus those that will not. The experiments proposed here were designed to measure changes in infancy through early childhood in offspring of mothers depressed during the prepartum and/or postpartum periods. In addition to assessing changes in child behavior, potential mediators of maternal depression on child development will be examined. The studies proposed are unique in that they are part of a larger study and the subject base is already very well characterized for both prepartum and postpartum depression (prospectively) such that the impact of lifetime history, prepartum and postpartum depression can be disentangled. Measuring early effects of maternal depression on offspring may shed some light on individual differences that may predict later impairment. In addition, since some data has already been collected on this population, it will be possible to look at some longitudinal changes in infants and children of depressed mothers.